David Kewley wrote:
...
> In our case, our racks are not yet fastened to the raised floor nor to the
> slab. In fact, we decided to leave them on their wheels. So they'll not
> be bound strongly at the plusses in your diagram, and the lateral force
> won't be too great. But yeah, in the common case where the racks are
> attached to the raised floor, you'll have the issue you name.
We set everything atop IsoBase isolation platforms, which
can move up to 8 inches in any lateral direction, letting
the floor move under the equipment racks.
http://www.worksafetech.com/pages/isobase.html
No other bracing is used, and each row of cabinents are
bolted together such that a single rack can't topple,
and the whole row of gear "floats" over the floor.
-skottie